Northern Dynasty Minerals Ltd (NAK)

[Scotttrader80]

POISON

When processing copper through heap leaching, vast quantities of ore and overburdenHelpoverburdenSoil and rocks that have been moved out of the way to get to ore are called "overburden." In areas where there are high concentrations of radionuclides in the rock, overburden may have some enhanced radioactivity, but not enough to mine and process. are mined. The overburden is separated and either hauled to the waste site or stockpiled for future site reclamation. The ore is crushed and stacked into specially designed pads. The pads are lined with synthetic or natural materials such as polyethylene or compacted clay.

Acids are introduced to copper-bearing ore, seeping through and dissolving copper and any other metals, including radionuclides. The liquid that “leaches” through the rocks is collected. This liquid contains the dissolved copper, known as a pregnant leach solution (PLS). The copper present in this liquid is collected and later processed.

A second method is in-situ leaching. Groundwater and certain geochemical conditions must be present in order to utilize this method. During in-situ leaching, rather than physically mining and removing overburden to reach copper deposits, chemicals are introduced into ore bodies using injection wells. The PLS is then captured in production wells, collected and later processed.

NAK=DEAD MONEY